Since the identification of the BRCA1 and BRCA2 breast cancer susceptibility genes, genetic testing has become increasingly widespread. Women who inherit a BRCA1/2 mutation have a 55-85 percent lifetime risk of breast cancer. The primary medical decision facing these women is whether to have a prophylactic mastectomy (breast removal) or to receive yearly mammograms. Because limited data favor one of these options or the other, women are informed about the benefits and limitations of each and counseled to select an option consistent with their personal preference and values. Although a specific recommendation for surgery versus surveillance is not generally made, BRCA1/2 carriers who do not elect surgery are advised to obtain annual mammograms. Given the lack of clear guidelines, it is not surprising that medical decision-making is reported to be one of the most challenging and stressful consequences of receiving a positive BRCA1/2 gene test result, and many carriers fail to adopt either option. The goal of this project is to develop and evaluate an interactive CD-ROM-based decision-aid for women who have recently received a positive BRCA1/2 gene test result. We propose a randomized trial among BRCA1 and BRCA2 mutation carriers in which we will compare standard genetic counseling (SGC) to an enhanced genetic counseling condition that consists of the individualized decision-aid (IDA) delivered in conjunction with standard genetic counseling. The IDA will be based, in part, on Subjective Expected Utility theory. Utility theory suggests that in making choices, people select the option that maximizes positive outcomes and minimizes negative outcomes. The value that an individual places on a particular health outcome is referred to as her preference or utility. Literature on decision-making in other medical contexts suggests that decision-aid interventions guided by Utility theory can promote informed decision-making and enhance psychological well being. If effective, the IDA can easily be disseminated to BRCA1/2 carriers across the country and adapted for use with other populations with inherited risk for cancer.